Download Simple Shift Installation and Tuning Guide for GM Trans Rev 1.2

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Simple Shift Installation and Tuning Guide
Transmission does not shift.
For the controller to command a shift, it requires power, ground, and vehicle speed. Power and
ground can be verified by observing that the Diag light turns on. Vehicle speed can be observed
from the Diag light. As vehicle speed increases, the Diag light should increase the rate of
flashing. If the status light flashes a different gear but no shift was felt verify the transmission
has power at the solenoid connector. If power is present but no shifting occurs have the
transmission checked by a qualified transmission service facility.
Diagnostic Code List
Simple Shift includes a complete list of OE-style diagnostic codes that have been programmed
to include ‘limp modes’ so that you do not get stranded if at all possible when the worst occurs.
These codes can be viewed on your Simple Shift through the Diag light found on the end panel
of your Simple Shift control unit and are invaluable pieces of information for the transmission
professional or knowledgeable do-it-yourselfer.
Important Note - Codes 24,39,68,69,71,74,75 are disabled if RPM knob is set to 0
Important Note - Codes 74,85,86,87 do not apply to 4L60E
Code Name
21
Throttle Position
High
22
Throttle Position
Low
24
Output Speed
Sensor
28
Range Pressure
Switch
37
Brake Switch Stuck
Off
38
Brake Switch Stuck
On
39
TCC Stuck Off
52
System Voltage
High Long
Conditions for code
Throttle position voltage has been
above 4.9 Volts for more than 1
second.
TPS voltage is less than 0.20 volts for
more than 6 seconds.
Not in Park or Neutral, Engine RPM
greater than 3000, Input shaft speed
greater than 2800, Throttle position
greater than 10%, Output Speed Less
than 200. All condition met for 3
seconds.
PCM/TCM must see one of two illegal
combinations from pressure switch
manifold.
Sets when Brake is not pressed,
Vehicle speed is between 5 and 22
mph for greater than 6 seconds, then
Vehicle speed is greater than 20 mph
for greater than 6 seconds, for a total
of 7 times.
Sets when Brake is pressed, Vehicle
speed is greater than 20 mph for
greater than 6 seconds. Vehicle
speed is between 5 and 22 mph for
greater than 6 seconds, for a total of 7
times.
TCC slip is greater than 65 RPM for 2
seconds.
Sets when system voltage is greater
than 16 volts for 10 minutes.
Powertrain Control Solutions, LLC.
Rev 1.2
Default condition on
fault
Maximum line pressure.
Shift points fixed at 35%
throttle.
Maximum line pressure.
Shift points fixed at 35%
throttle.
2nd Gear with Maximum line
pressure.
Maximum pressure.
Assume Overdrive 4 is
selected.
None.
None.
None.
2nd Gear with Maximum line
pressure. Inhibit TCC.
804.227.3023